Various and numerous sulfonated and otherwise derived lignin materials have already been found, known and developed and advantageously applied for many useful and beneficial purposes.
Numerous references are available dealing in one way or another with the identity and nature of lignin, per se and many of the derivatives of lignin including lignosulfonates (all of which, by the way, are, generally, relatively imprecise and not positively definite), preparation and numerous uses of such materials, substantial information thereon may be found, by way of illustration, in U.S. Pats. Nos. 1,848,292; 2,371,136; 2,371,137; 2,491,832; 2,505,304; 2,576,418; 2,598,311; 2,800.449; 3,087,923; 3,156,520; and 3,726,850. Still additional art of interest is uncovered in U.S. Pats. Nos. Re. 18,268 2,057,117; 2,104,701; 2,399,607; and 2,434,626.
Another excellent informational source in this area is the Bulletin (No. 131) published by AMERICAN CAN COMPANY of Greenwich, Connecticut 06830 (U.S.A.) entitled "Chemicals From Wood".
The lignosulfonates which are utilized as the starting materials in practice of and to obtain the novel ozonated compositions of the present invention are the treated or untreated spent sulfite liquors (i.e., containing the desired effluent lignosulfonate solids) obtained from wood conversion as the sulfite waste pulping liquor. These, as indicated, may be ozonated in the "as is" or whole liquor condition. Or, and oftentimes with advantage, they may be ozonated as a purified lignosulfonate material from or in which the sugars and other saccharide constituents have been removed and/or destroyed or, additionally, inorganic constituents have also been partially or fully eliminated. As a further alternative, the lignosulfonate material that is ozonated may be one of the desulfonated lignosulfonates (including substantially pure lignosulfonate compositions) which are generally obtained by catalytic -- frequently alkaline --oxidation processes conducted under conditions of high temperature and pressure, oftentimes with accompanying hydrolysis.
Where alkaline oxidized, hydrolyzed, partially desulfonated lignosulfonates are utilized as the starting materials in practice of and to obtain the novel ozonated compositions of the present invention, they are usually most readily and conveniently obtained pursuant to the teachings of U.S. Pat. No. 2,491,832.
In this connection, the lignosulfonate material that is utilized for ozonization may be, and frequently with great benefit, is a resulfonated desulfonated lignosulfonate product of the type prepared according to the teachings and disclosures of the present Applicant's copending Application with another co-Applicant for U.S. Letters Patent entitled "SOLUBILIZED RESULFONATED LIGNOSULFONATES" having Ser. No. 671,397 which was filed Mar. 29, 1976 (wherein there are also described various of the lignosulfonate materials that are suitable to be ozonated in practice of the present invention).
In general, the lignosulfonates are anionic polyelectrolytes with a relative molecular size usually on the order of 1,000 to 20,000 and from which the ozonated products are obtained according to the instant invention. They generally have an organic sulfonic sulfur, i.e., --SO.sub.3, content calculated as percent sulfur by weight of broadly between about 1/2 and about 15 wt. %. More advantageously for many purposes, this sulfur range is between about 1 1/2 or 1 3/4 and about 10 wt. %; while quite often it is preferable for the partially desulfonated lignosulfonate to contain from about 2 to about 8 wt. % of the combined sulfur which represents its appearance in the sulfonic form.
Many of the lignosulfonates that are advantageously ozonated according to practice of the present invention are obtained in waste pulping liquors derived from a totally, or at least substantially, softwood source. However, excellent ozonated lignosulfonate products are also prepared from hardwood starting materials.
Good examples of lignosulfonate products of various types which are commercially available from AMERICAN CAN COMPANY include those having the Trademarks "MARASPERSE C21", "MARASPERSE CB" and "MARASPERSE N-22". These are generally derived from softwood sulfite waste pulping liquors, with "MARASPERSE N-22" being considerably refined as to sugars and certain inorganics contents and "MARASPERSE CB" being a sulfonated spent oxidized liquor residue from a vanillin recovery process as taught in the above-identified U.S. Pat. No. 2,491,832.
As usually available, these commercial ignosulfonates generally have the following typical analyses and physical characteristics features: TYPICAL ANALYSIS (Moisture-Free and Wt. % Basis):
__________________________________________________________________________ "MARASPERSE "MARASPERSE "MARASPERSE C-21" CB" N-22" __________________________________________________________________________ pH-3% Solution 7.0-8.2 8.5-9.2 7.5-8.5 Total Sulfur as S, % 6.8 2.6 7.3 Sulfate Sulfur as S, % 0.3 0.1 1.0 Sulfite Sulfur as S, % 0.09 0 0.12 CaO, % 5.2 0.03 0.55 MgO, % 0.3 Trace 0.3 Na.sub.2 O, % 6.1 9.9 13.2 Reducing sugars, % 1.5 0 0.8 OCH.sub.3, % 7.9 12.7 7.7 __________________________________________________________________________
______________________________________ PHYSICAL CHARACTERISTICS ______________________________________ Usual Form Powder Powder Powder Moisture Content 7.5 8.0 7.0 (Max., % H.sub.2 O) Color Brown Black Brown Bulk Density 35-40 43-47 35-40 (lbs./cu. ft.) Solubility in Water (%) 100 100 100 Solubility in Oils and Most Organic Solvents (%) 0 0 0 Surface Tension, 1% Sol'n (in dynes/cm) ca. 49.4 ca. 51.4 ca. 52.8 ______________________________________
Another good lignosulfonate material (also commercially available from AMERICAN CAN COMPANY) is a hardwood lignosulfonate known as MARASPERSE (TM) N-42 lignosulfonate. This material has an analysis and characteristics generally quite analogous to those of MARASPERSE (TM) N-22 lignosulfonate. NORLIG (TM) 41 lignosulfonate, likewise commercially available from AMERICAN CAN COMPANY, is a still further illustration of a crude spent sulfite lignosulfonate material that is advantageously benefited in accordance with practice of the present invention (its typical analyses and characteristics being set forth in the above-identified Bulletin No. 131).
While the known lignosulfonate products, including such things as the above mentioned "MARASPERSE" materials, are good surfactant, dispersant, detergent and otherwise attractively-propertied materials that are commendable for a wide variety of uses, they still have certain intrinsic inadequacies and limitations leaving some desiderata and unfulfilled capability for use in many crucial applications and for expanded applicability in and for many highly advantageous purposes. Noteworthy amongst these are difficulties in the employment of the mentioned partial desulfonated lignosulfonates due to their relatively limited solubility in saline solutions plus their sometimes not totally satisfactory potential for having extraordinarily superb general surfactant exhibitions.